Ultrasound probe for tissue treatment

ABSTRACT

A method and system for providing ultrasound treatment to a tissue that contains a lower part of dermis and proximal protrusions of fat lobuli into the dermis. An embodiment delivers ultrasound energy to the region creating a thermal injury and coagulating the proximal protrusions of fat lobuli, thereby eliminating the fat protrusions into the dermis. An embodiment can also include ultrasound imaging configurations using the same or a separate probe before, after or during the treatment. In addition various therapeutic levels of ultrasound can be used to increase the speed at which fat metabolizes. Additionally the mechanical action of ultrasound physically breaks fat cell clusters and stretches the fibrous bonds. Mechanical action will also enhance lymphatic drainage, stimulating the evacuation of fat decay products.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/996,295, filed Jun. 1, 2018, now U.S. Pat. No. 10,245,450, which is acontinuation of U.S. patent application Ser. No. 15/821,281 filed Nov.22, 2017, now U.S. Pat. No. 10,010,725, which is a continuation of U.S.patent application Ser. No. 15/650,246 filed Jul. 14, 2017, now U.S.Pat. No. 9,827,450, which is a continuation of U.S. patent applicationSer. No. 15/374,918 filed Dec. 9, 2016, now U.S. Pat. No. 9,707,412,which is a continuation of U.S. application Ser. No. 15/041,829 filedFeb. 11, 2016, now U.S. Pat. No. 9,522,290, which is a continuation ofU.S. application Ser. No. 14/550,720 filed Nov. 21, 2014, now U.S. Pat.No. 9,283,410, which is a continuation of U.S. application Ser. No.14/164,598 filed Jan. 27, 2014, now U.S. Pat. No. 8,915,854, which is acontinuation of U.S. application Ser. No. 13/789,562 filed Mar. 7, 2013,now U.S. Pat. No. 8,636,665, which is a continuation of U.S. applicationSer. No. 13/356,405 filed Jan. 23, 2012, now U.S. Pat. No. 8,672,848,which is a continuation of U.S. application Ser. No. 11/163,154 filed onOct. 6, 2005, now U.S. Pat. No. 8,133,180, which claims the benefit ofpriority to U.S. Provisional No. 60/616,753, filed on Oct. 6, 2004, eachof which are hereby incorporated by reference in their entirety herein.Any and all priority claims identified in the Application Data Sheet, orany correction thereto, are hereby incorporated by reference under 37CFR 1.57.

BACKGROUND Field of the Invention

The present invention relates to ultrasound therapy systems, and inparticular to a method and system for treating cellulite.

Description of the Related Art

Cellulite is a common skin disorder that appears as an irregularity ofskin contour, often characterized by a dimple appearance of the skin.This condition affects 80% of women worldwide and tends to gathersuperficially around the thighs, hips, and buttocks.

Cellulite develops in the body when fat is deposited immediately belowthe dermis and contained in fat chambers (lobuli) that can becomeswollen. As the fat cells grow in size, lobuli tend to protrude into adermis layer, surrounding tissue becomes compressed and hardened, makingblood circulation more difficult in trapping fluids. Reduced elasticityof the adipose tissue produces an undesirable tension between thelayers. The resulting protrusions and depressions of connective tissueanchor points create the appearance of cellulite.

This condition responds with varying results to invasive procedures,such as liposuction. The non-invasive technologies such as massagers,and low frequency ultrasound diathermy, show marginal results.Preliminary results shown by combination of infrared light and RF energyhave some promise of improving skin contours, but significant progressis needed.

SUMMARY

In accordance with various aspects of the present invention, a methodand system for non-invasive treatment of cellulite with ultrasound areprovided. An exemplary treatment method and system comprises atherapeutic ultrasound system for providing ultrasound treatment to adeep tissue region that contains a lower part of dermis and proximalprotrusions of fat lobuli into the dermis. Such an exemplary treatmentsystem delivers conformal ultrasound therapeutic energy to the regioncreating a thermal injury and coagulating the proximal protrusions offat lobuli, thereby eliminating the fat protrusions into the dermis thedermis resulting in improved appearance of the overlaying superficiallayers of the skin. In accordance with exemplary embodiments, anexemplary treatment system may include ultrasound imaging mechanismsusing the same or a separate probe before, after or during thetreatment. Other imaging configurations can be utilized to image,monitor, and provide feedback of ultrasound therapy, such as MRI, X-Ray,PET, infrared or others.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the invention is particularly pointed out in theconcluding portion of the specification. The invention, however, both asto organization and method of operation, may best be understood byreference to the following description taken in conjunction with theaccompanying drawing figures, in which like parts may be referred to bylike numerals:

FIG. 1 illustrates a block diagram of an exemplary ultrasound treatmentsystem for treating cellulite in accordance with an exemplary embodimentof the present invention;

FIG. 2 illustrates a cross sectional diagram of an exemplary probesystem in accordance with exemplary embodiments of the presentinvention;

FIGS. 3A and 3B illustrate block diagrams of an exemplary control systemin accordance with exemplary embodiments of the present invention;

FIGS. 4A and 4B illustrate block diagrams of an exemplary probe systemin accordance with exemplary embodiments of the present invention;

FIG. 5 illustrates a cross-sectional diagram of an exemplary transducerin accordance with an exemplary embodiment of the present invention;

FIGS. 6A and 6B illustrate cross-sectional diagrams of an exemplarytransducer in accordance with exemplary embodiments of the presentinvention;

FIG. 7 illustrates exemplary transducer configurations for ultrasoundtreatment in accordance with various exemplary embodiments of thepresent invention;

FIGS. 8A and 8B illustrate cross-sectional diagrams of an exemplarytransducer in accordance with another exemplary embodiment of thepresent invention;

FIG. 9 illustrates an exemplary transducer configured as atwo-dimensional array for ultrasound treatment in accordance with anexemplary embodiment of the present invention;

FIGS. 10A-10F illustrate cross-sectional diagrams of exemplarytransducers in accordance with other exemplary embodiments of thepresent invention;

FIG. 11 illustrates a schematic diagram of an acoustic coupling andcooling system in accordance with an exemplary embodiment of the presentinvention; and

FIG. 12 illustrates a block diagram of a treatment system comprising anultrasound treatment subsystem combined with additional subsystems andmethods of treatment monitoring and/or treatment imaging as well as asecondary treatment subsystem in accordance with an exemplary embodimentof the present invention.

DETAILED DESCRIPTION

The present invention may be described herein in terms of variousfunctional components and processing steps. It should be appreciatedthat such components and steps may be realized by any number of hardwarecomponents configured to perform the specified functions. For example,the present invention may employ various medical treatment devices,visual imaging and display devices, input terminals and the like, whichmay carry out a variety of functions under the control of one or morecontrol systems or other control devices. In addition, the presentinvention may be practiced in any number of medical contexts and thatthe exemplary embodiments relating to a non-invasive cellulite treatmentsystem as described herein are merely indicative of exemplaryapplications for the invention. For example, the principles, featuresand methods discussed may be applied to any medical application.Further, various aspects of the present invention may be suitablyapplied to other applications.

In accordance with various aspects of the present invention, anon-invasive method and system for treating cellulite are provided. Forexample, in accordance with an exemplary embodiment, with reference toFIG. 1, an exemplary treatment system 100 configured to treat a regionof interest 106 comprises a control system 102, an imaging/therapy probewith acoustic coupling 104, and a display system 108.

Control system 102 and display system 108 can comprise variousconfigurations for controlling probe 104 and overall system 100functionality, such as, for example, a microprocessor with software anda plurality of input/output devices, system and devices for controllingelectronic and/or mechanical scanning and/or multiplexing oftransducers, a system for power delivery, systems for monitoring,systems for sensing the spatial position of the probe and/ortransducers, and/or systems for handling user input and recordingtreatment results, among others. Imaging/therapy probe 104 can comprisevarious probe and/or transducer configurations. For example, probe 104can be configured for a combined dual-mode imaging/therapy transducer,coupled or co-housed imaging/therapy transducers, or simply a separatetherapy probe and an imaging probe.

In accordance with an exemplary embodiment, treatment system 100 isconfigured for treating a deep tissue region that contains a lower partof dermis and proximal protrusions of fat lobuli into the dermis, byfirst, imaging of region of interest 106 for localization of thetreatment area and surrounding structures, second, delivery ofultrasound energy at a depth, distribution, timing, and energy level toachieve the desired therapeutic effect, and third to monitor thetreatment area before, during, and after therapy to plan and assess theresults and/or provide feedback. As to the delivery of energy, controlsystem 102 and transducer system 102 can be suitably configured todeliver conformal ultrasound therapeutic energy to ROI 106 creating athermal injury and coagulating the proximal protrusions of fat lobuli,thereby eliminating the fat protrusions into the dermis. As used herein,the term “dermis” refers to any part of the dermis and/or the epidermis.

In addition, by treatment of ROI 106, transducer system 102 may beconfigured to deliver one or more energy fields to promote one or moreeffects, for example, ablation of existing tissue, the breaking up offat cell clusters, stretching of the fibrous bonds, enhancement oflymphatic drainage, stimulation of the evacuation of fat decay products,and/or enhanced cell permeability in order to treat cellulite.

An exemplary ultrasound therapy system of FIG. 1 is further illustratedin an exemplary embodiment in FIG. 2. A therapy transducer system 200includes a transducer probe 202 connected to a control system 204, anddisplay 206, in combination may provide therapy, imaging, and/ortemperature or other tissue parameters monitoring to region of interest210. Exemplary transducer system 200 is configured for first, imagingand display of region of interest 210 for localization of the treatmentarea and surrounding structures, second, delivery of focused, unfocused,or defocused ultrasound energy at a depth, distribution, timing, andenergy level to achieve the desired therapeutic effect of thermalablation to treat cellulite, and third to monitor the treatment area andsurrounding structures before, during, and after therapy to plan andassess the results and/or provide feedback to control system 204 and/oran operator.

Exemplary transducer probe 202 can be configured to be suitablycontrolled and/or operated in various manners. For example, transducerprobe 202 may be configured for use within an ultrasound treatmentsystem, an ultrasound imaging system and/or an ultrasound imaging,therapy, and/or treatment monitoring system, including motion controlsubsystems.

Control system 204 can be configured with one or more subsystems,processors, input devices, displays and/or the like. Display 206 may beconfigured to image and/or monitor ROI 210 and/or any particularsub-region within ROI 210. Display 206 can be configured fortwo-dimensional, three-dimensional, real-time, analog, digital and/orany other type of imaging. Exemplary embodiments of both control system204 and display 206 are described in greater detail herein.

Region of interest 210, can be comprised of superficial layer(epidermis/dermis) subcutaneous fat, lobuli, and muscle. Exemplarytransducer system 200, is configured to provide cross-sectionaltwo-dimensional imaging of the region 207, displayed as an image 205,with a controlled thermal lesion 209, confined approximately to proximalportion of fat lobuli and lower portion of dermis.

Transducer system 200 can be configured with the ability to controllablyproduce conformal treatment areas in superficial human tissue withinregion of interest 210 through precise spatial and temporal control ofacoustic energy deposition. In accordance with an exemplary embodiment,control system 204 and transducer probe 202 can be suitably configuredfor spatial control of the acoustic energy by controlling the manner ofdistribution of the acoustical energy. For example, spatial control maybe realized through selection of the type of one or more transducerconfigurations insonifying region of interest 210, selection of theplacement and location of transducer probe 202 for delivery ofacoustical energy relative to region-of-interest 210, e.g., transducerprobe 202 configured for scanning over part or whole ofregion-of-interest 210 to deliver conformal ultrasound therapeuticenergy to create a thermal injury and to coagulate the proximalprotrusions of fat lobuli, thereby eliminating the fat protrusions intothe dermis. Transducer probe 202 may also be configured for control ofother environment parameters, e.g., the temperature at the acousticcoupling interface can be controlled. In addition to the spatialcontrol, control system 204 and/or transducer probe 202 can also beconfigured for temporal control, such as through adjustment andoptimization of drive amplitude levels, frequency/waveform selections,and timing sequences and other energy drive characteristics to controlthe treatment of tissue. The spatial and/or temporal control can also befacilitated through open-loop and closed-loop feedback arrangements,such as through the monitoring of various positional and temporalcharacteristics. For example, through such spatial and/or temporalcontrol, an exemplary treatment system 200 can enable the regions ofthermal injury to possess arbitrary shape and size and allow the tissueto be treated in a controlled manner.

Transducer system 200 may be used to provide a mechanical action ofultrasound to physically break fat cell clusters and stretch the fibrousbonds. This mechanical action will also enhance lymphatic drainage,stimulating the evacuation of fat decay products. That is, theultrasound may facilitate movement of the muscles and soft tissueswithin ROI 210, thereby facilitating the loosening of fat depositsand/or the break up of fibrous tissue surrounding fat deposits.

In addition, transducer system 200 can be configured to deliver varioustherapeutic levels of ultrasound to increase the speed at which fatmetabolizes, according to the Arrhenius Law: Y=Ae^(−B/T), where Y is theyield of metabolic reaction, A and B are constants, and T is thetemperature in degrees Kelvin. In one exemplary embodiment, transducersystem 200 is configured to provide various therapeutic levels ofultrasound to increase the speed at which fat metabolizes. That is,according to Arrhenius Law, the yield, Y of a metabolic reaction is afunction of temperature, T: Y=Ae^(−B/T), where A and B are constants,and T is the temperature in degrees Kelvin. Thus, ultrasound treatmentfrom transducer system 200, ranging from approximately 750 kHz to 20MHz, can increase the temperature in a treatment area, therebyincreasing the metabolic reaction yield for that treatment area.

As previously described, control systems 104 and 204 may be configuredin various manners with various subsystems and subcomponents. Withreference to FIGS. 3A and 3B, in accordance with exemplary embodiments,an exemplary control system 300 can be configured for coordination andcontrol of the entire therapeutic treatment process in accordance withthe adjustable settings made by a therapeutic treatment system user. Forexample, control system 300 can suitably comprise power sourcecomponents 302, sensing and monitoring components 304, cooling andcoupling controls 306, and/or processing and control logic components308. Control system 300 can be configured and optimized in a variety ofways with more or less subsystems and components to implement thetherapeutic system for cellulite treatment, and the embodiment in FIGS.3A and 3B are merely for illustration purposes.

For example, for power sourcing components 302, control system 300 cancomprise one or more direct current (DC) power supplies 303 configuredto provide electrical energy for entire control system 300, includingpower required by a transducer electronic amplifier/driver 312. A DCcurrent sense device 305 can also be provided to confirm the level ofpower going into amplifiers/drivers 312 for safety and monitoringpurposes.

Amplifiers/drivers 312 can comprise multi-channel or single channelpower amplifiers and/or drivers. In accordance with an exemplaryembodiment for transducer array configurations, amplifiers/drivers 312can also be configured with a beamformer to facilitate array focusing.An exemplary beamformer can be electrically excited by anoscillator/digitally controlled waveform synthesizer 310 with relatedswitching logic.

The power sourcing components can also include various filteringconfigurations 314. For example, switchable harmonic filters and/ormatching may be used at the output of amplifier/driver 312 to increasethe drive efficiency and effectiveness. Power detection components 316may also be included to confirm appropriate operation and calibration.For example, electric power and other energy detection components 316may be used to monitor the amount of power going to an exemplary probesystem.

Various sensing and monitoring components 304 may also be suitablyimplemented within control system 300. For example, in accordance withan exemplary embodiment, monitoring, sensing and interface controlcomponents 324 may be configured to operate with various motiondetection systems 322 implemented within transducer probe 104 to receiveand process information such as acoustic or other spatial and temporalinformation from a region of interest. Sensing and monitoring componentscan also include various controls, interfacing and switches 309 and/orpower detectors 316. Such sensing and monitoring components 304 canfacilitate open-loop and/or closed-loop feedback systems withintreatment system 100.

For example, In such an open-loop system, a system user can suitablymonitor the imaging and/or other spatial or temporal parameters and thenadjust or modify same to accomplish a particular treatment objective.Instead of, or in combination with open-loop feedback configurations, anexemplary treatment system can comprise a closed-loop feedback system,wherein images and/or spatial/temporal parameters can be suitablymonitored within monitoring component to generate signals.

During operation of exemplary treatment system 100, a lesionconfiguration of a selected size, shape, orientation is determined.Based on that lesion configuration, one or more spatial parameters areselected, along with suitable temporal parameters, the combination ofwhich yields the desired conformal lesion. Operation of the transducercan then be initiated to provide the conformal lesion or lesions. Openand/or closed-loop feedback systems can also be implemented to monitorthe spatial and/or temporal characteristics, and/or other tissueparameter monitoring, to further control the conformal lesions.

Cooling/coupling control systems 306 may be provided to remove wasteheat from exemplary probe 104, provide a controlled temperature at thesuperficial tissue interface and deeper into tissue, and/or provideacoustic coupling from transducer probe 104 to region-of-interest 106.Such cooling/coupling control systems 306 can also be configured tooperate in both open-loop and/or closed-loop feedback arrangements withvarious coupling and feedback components.

Processing and control logic components 308 can comprise various systemprocessors and digital control logic 307, such as one or more ofmicrocontrollers, microprocessors, field-programmable gate arrays(FPGAs), computer boards, and associated components, including firmwareand control software 326, which interfaces to user controls andinterfacing circuits as well as input/output circuits and systems forcommunications, displays, interfacing, storage, documentation, and otheruseful functions. System software and firmware 326 controls allinitialization, timing, level setting, monitoring, safety monitoring,and all other system functions required to accomplish user-definedtreatment objectives. Further, various control switches 308 can also besuitably configured to control operation.

An exemplary transducer probe 104 can also be configured in variousmanners and comprise a number of reusable and/or disposable componentsand parts in various embodiments to facilitate its operation. Forexample, transducer probe 104 can be configured within any type oftransducer probe housing or arrangement for facilitating the coupling oftransducer to a tissue interface, with such housing comprising variousshapes, contours and configurations depending on the particulartreatment application. For example, in accordance with an exemplaryembodiment, transducer probe 104 can be depressed against a tissueinterface whereby blood perfusion is partially or wholly cut-off, andtissue flattened in superficial treatment region-of-interest 106.Transducer probe 104 can comprise any type of matching, such as forexample, electric matching, which may be electrically switchable;multiplexer circuits and/or aperture/element selection circuits; and/orprobe identification devices, to certify probe handle, electricmatching, transducer usage history and calibration, such as one or moreserial EEPROM (memories). Transducer probe 104 may also comprise cablesand connectors; motion mechanisms, motion sensors and encoders; thermalmonitoring sensors; and/or user control and status related switches, andindicators such as LEDs. For example, a motion mechanism in probe 104may be used to controllably create multiple lesions, or sensing of probemotion itself may be used to controllably create multiple lesions and/orstop creation of lesions, e.g. for safety reasons if probe 104 issuddenly jerked or is dropped. In addition, an external motion encoderarm may be used to hold the probe during use, whereby the spatialposition and attitude of probe 104 is sent to the control system to helpcontrollably create lesions. Furthermore, other sensing functionalitysuch as profilometers or other imaging modalities may be integrated intothe probe in accordance with various exemplary embodiments.

With reference to FIGS. 4A and 4B, in accordance with an exemplaryembodiment, a transducer probe 400 can comprise a control interface 402,a transducer 404, coupling components 406, and monitoring/sensingcomponents 408, and/or motion mechanism 410. However, transducer probe400 can be configured and optimized in a variety of ways with more orless parts and components to provide ultrasound energy for cellulitetreatment, and the embodiment in FIGS. 4A and 4B are merely forillustration purposes.

In accordance with an exemplary embodiment of the present invention,transducer probe 400 is configured to deliver energy over varyingtemporal and/or spatial distributions in order to provide energy effectsand initiate responses in a region of interest. These effects caninclude, for example, thermal, cavitational, hydrodynamic, and resonanceinduced tissue effects. For example, exemplary transducer probe 400 canbe operated under one or more frequency ranges to provide two or moreenergy effects and initiate one or more responses in the region ofinterest. In addition, transducer probe 400 can also be configured todeliver planar, defocused and/or focused energy to a region of interestto provide two or more energy effects and to initiate one or morereactions. These responses can include, for example, diathermy,hemostasis, revascularization, angiogenesis, growth of interconnectivetissue, tissue reformation, ablation of existing tissue, proteinsynthesis and/or enhanced cell permeability. These and various otherexemplary embodiments for such combined ultrasound treatment, effectsand responses are more fully set forth in U.S. patent application Ser.No. 10/950,112, entitled “METHOD AND SYSTEM FOR COMBINED ULTRASOUNDTREATMENT,” Filed Sep. 24, 2004 and incorporated herein by reference.

Control interface 402 is configured for interfacing 428 with controlsystem 300 to facilitate control of transducer probe 400. Controlinterface components 402 can comprise multiplexer/aperture select 424,switchable electric matching networks 426, serial EEPROMs and/or otherprocessing components and matching and probe usage information 430 andinterface connectors 432.

Coupling components 406 can comprise various devices to facilitatecoupling of transducer probe 400 to a region of interest. For example,coupling components 406 can comprise cooling and acoustic couplingsystem 420 configured for acoustic coupling of ultrasound energy andsignals. Acoustic cooling/coupling system 420 with possible connectionssuch as manifolds may be utilized to couple sound into theregion-of-interest, control temperature at the interface and deeper intotissue, provide liquid-filled lens focusing, and/or to remove transducerwaste heat. Coupling system 420 may facilitate such coupling through useof various coupling mediums, including air and other gases, water andother fluids, gels, solids, and/or any combination thereof, or any othermedium that allows for signals to be transmitted between transduceractive elements 412 and a region of interest. In addition to providing acoupling function, in accordance with an exemplary embodiment, couplingsystem 420 can also be configured for providing temperature controlduring the treatment application. For example, coupling system 420 canbe configured for controlled cooling of an interface surface or regionbetween transducer probe 400 and a region of interest and beyond andbeyond and beyond by suitably controlling the temperature of thecoupling medium. The suitable temperature for such coupling medium canbe achieved in various manners, and utilize various feedback systems,such as thermocouples, thermistors or any other device or systemconfigured for temperature measurement of a coupling medium. Suchcontrolled cooling can be configured to further facilitate spatialand/or thermal energy control of transducer probe 400.

In accordance with an exemplary embodiment, with additional reference toFIG. 11, acoustic coupling and cooling 1140 can be provided toacoustically couple energy and imaging signals from transducer 1104 toand from the region of interest 1102, to provide thermal control at theprobe 1100 to region-of-interest interface 1110, and to remove potentialwaste heat from the transducer probe at region 1144. Temperaturemonitoring can be provided at the coupling interface via a thermalsensor 1146 to provide a mechanism of temperature measurement 1148 andcontrol via control system 1106 and a thermal control system 1142.Thermal control may consist of passive cooling such as via heat sinks ornatural conduction and convection or via active cooling such as withpeltier thermoelectric coolers, refrigerants, or fluid-based systemscomprised of pump, fluid reservoir, bubble detection, flow sensor, flowchannels/tubing 1144 and thermal control 1142.

Monitoring and sensing components 408 can comprise various motion and/orposition sensors 416, temperature monitoring sensors 418, user controland feedback switches 414 and other like components for facilitatingcontrol by control system 300, e.g., to facilitate spatial and/ortemporal control through open-loop and closed-loop feedback arrangementsthat monitor various spatial and temporal characteristics.

Motion mechanism 410 can comprise manual operation, mechanicalarrangements, or some combination thereof. For example, a motionmechanism 422 can be suitably controlled by control system 300, such asthrough the use of accelerometers, encoders or otherposition/orientation devices 416 to determine and enable movement andpositions of transducer probe 400. Linear, rotational or variablemovement can be facilitated, e.g., those depending on the treatmentapplication and tissue contour surface.

Transducer 404 can comprise one or more transducers configured forproducing conformal lesions of thermal injury in superficial humantissue within a region of interest through precise spatial and temporalcontrol of acoustic energy deposition. Transducer 404 can also compriseone or more transduction elements and/or lenses 412. The transductionelements can comprise a piezoelectrically active material, such as leadzirconate titanate (PZT), or any other piezoelectrically activematerial, such as a piezoelectric ceramic, crystal, plastic, and/orcomposite materials, as well as lithium niobate, lead titanate, bariumtitanate, and/or lead metaniobate. In addition to, or instead of, apiezoelectrically active material, transducer 404 can comprise any othermaterials configured for generating radiation and/or acoustical energy.Transducer 404 can also comprise one or more matching layers configuredalong with the transduction element such as coupled to thepiezoelectrically active material. Acoustic matching layers and/ordamping may be employed as necessary to achieve the desiredelectroacoustic response.

In accordance with an exemplary embodiment, the thickness of thetransduction element of transducer 404 can be configured to be uniform.That is, a transduction element 412 can be configured to have athickness that is substantially the same throughout. In accordance withanother exemplary embodiment, the thickness of a transduction element412 can also be configured to be variable. For example, transductionelement(s) 412 of transducer 404 can be configured to have a firstthickness selected to provide a center operating frequency of a lowerrange, for example from approximately 750 kHz to 5 MHz. Transductionelement 404 can also be configured with a second thickness selected toprovide a center operating frequency of a higher range, for example fromapproximately 5 MHz to 20 MHz or more. Transducer 404 can be configuredas a single broadband transducer excited with at least two or morefrequencies to provide an adequate output for generating a desiredresponse. Transducer 404 can also be configured as two or moreindividual transducers, wherein each transducer comprises one or moretransduction element. The thickness of the transduction elements can beconfigured to provide center-operating frequencies in a desiredtreatment range. For example, transducer 404 can comprise a firsttransducer configured with a first transduction element having athickness corresponding to a center frequency range of approximately 750kHz to 5 MHz, and a second transducer configured with a secondtransduction element having a thickness corresponding to a centerfrequency of approximately 5 MHz to 20 MHz or more.

Transducer 404 may be composed of one or more individual transducers inany combination of focused, planar, or unfocused single-element,multi-element, or array transducers, including 1-D, 2-D, and annulararrays; linear, curvilinear, sector, or spherical arrays; spherically,cylindrically, and/or electronically focused, defocused, and/or lensedsources. For example, with reference to an exemplary embodiment depictedin FIG. 5, transducer 500 can be configured as an acoustic array tofacilitate phase focusing. That is, transducer 500 can be configured asan array of electronic apertures that may be operated by a variety ofphases via variable electronic time delays. By the term “operated,” theelectronic apertures of transducer 500 may be manipulated, driven, used,and/or configured to produce and/or deliver an energy beam correspondingto the phase variation caused by the electronic time delay. For example,these phase variations can be used to deliver defocused beams 508,planar beams 504, and/or focused beams 506, each of which may be used incombination to achieve different physiological effects in a region ofinterest 510. Transducer 500 may additionally comprise any softwareand/or other hardware for generating, producing and/or driving a phasedaperture array with one or more electronic time delays.

Transducer 500 can also be configured to provide focused treatment toone or more regions of interest using various frequencies. In order toprovide focused treatment, transducer 500 can be configured with one ormore variable depth devices to facilitate treatment. For example,transducer 500 may be configured with variable depth devices disclosedin U.S. patent application Ser. No. 10/944,500, entitled “System andMethod for Variable Depth Ultrasound”, filed on Sep. 16, 2004, having atleast one common inventor and a common Assignee as the presentapplication, and incorporated herein by reference. In addition,transducer 500 can also be configured to treat one or more additionalROI 510 through the enabling of sub-harmonics or pulse-echo imaging, asdisclosed in U.S. patent application Ser. No. 10/944,499, entitled“Method and System for Ultrasound Treatment with a Multi-directionalTransducer”, filed on Sep. 16, 2004, having at least one common inventorand a common Assignee as the present application, and also incorporatedherein by reference.

Moreover, any variety of mechanical lenses or variable focus lenses,e.g. liquid-filled lenses, may also be used to focus and/or defocus thesound field. For example, with reference to exemplary embodimentsdepicted in FIGS. 6A and 6B, transducer 600 may also be configured withan electronic focusing array 604 in combination with one or moretransduction elements 606 to facilitate increased flexibility intreating ROI 610. Array 602 may be configured in a manner similar totransducer 502. That is, array 602 can be configured as an array 604 ofelectronic apertures that may be operated by a variety of phases viavariable electronic time delays, for example, T₁, T₂ . . . T_(j). By theterm “operated,” the electronic apertures of array 604 may bemanipulated, driven, used, and/or configured to produce and/or deliverenergy in a manner corresponding to the phase variation caused by theelectronic time delay. For example, these phase variations can be usedto deliver defocused beams, planar beams, and/or focused beams, each ofwhich may be used in combination to achieve different physiologicaleffects in ROI 610.

Transduction elements 606 may be configured to be concave, convex,and/or planar. For example, in an exemplary embodiment depicted in FIG.6A, transduction elements 606 are configured to be concave in order toprovide focused energy for treatment of ROI 610. Additional embodimentsare disclosed in U.S. patent application Ser. No. 10/944,500, entitled“Variable Depth Transducer System and Method”, and again incorporatedherein by reference.

In another exemplary embodiment, depicted in FIG. 6B, transductionelements 606 can be configured to be substantially flat in order toprovide substantially uniform energy to ROI 610. While FIGS. 6A and 6Bdepict exemplary embodiments with transduction elements 604 configuredas concave and substantially flat, respectively, transduction elements604 can be configured to be concave, convex, and/or substantially flat.In addition, transduction elements 604 can be configured to be anycombination of concave, convex, and/or substantially flat structures.For example, a first transduction element can be configured to beconcave, while a second transduction element can be configured to besubstantially flat.

With reference to FIGS. 8A and 8B, transducer 800 can be configured assingle-element arrays, wherein a single-element 802, e.g., atransduction element of various structures and materials, can beconfigured with a plurality of masks 804, such masks comprising ceramic,metal or any other material or structure for masking or altering energydistribution from element 802, creating an array of energy distributions808. Masks 804 can be coupled directly to element 802 or separated by astandoff 806, such as any suitably solid or liquid material.

An exemplary transducer 404 can also be configured as an annular arrayto provide planar, focused and/or defocused acoustical energy. Forexample, with reference to FIGS. 10A and 10B, in accordance with anexemplary embodiment, an annular array 1000 can comprise a plurality ofrings 1012, 1014, 1016 to N. Rings 1012, 1014, 1016 to N can bemechanically and electrically isolated into a set of individualelements, and can create planar, focused, or defocused waves. Forexample, such waves can be centered on-axis, such as by methods ofadjusting corresponding transmit and/or receive delays, τ₁, τ₂, τ₃ . . .τ_(N). An electronic focus can be suitably moved along various depthpositions, and can enable variable strength or beam tightness, while anelectronic defocus can have varying amounts of defocusing. In accordancewith an exemplary embodiment, a lens and/or convex or concave shapedannular array 1000 can also be provided to aid focusing or defocusingsuch that any time differential delays can be reduced. Movement ofannular array 1000 in one, two or three-dimensions, or along any path,such as through use of probes and/or any conventional robotic armmechanisms, may be implemented to scan and/or treat a volume or anycorresponding space within a region of interest.

Transducer 404 can also be configured in other annular or non-arrayconfigurations for imaging/therapy functions. For example, withreference to FIGS. 10C-10F, a transducer can comprise an imaging element1012 configured with therapy element(s) 1014. Elements 1012 and 1014 cancomprise a single-transduction element, e.g., a combinedimaging/transducer element, or separate elements, can be electricallyisolated 1022 within the same transduction element or between separateimaging and therapy elements, and/or can comprise standoff 1024 or othermatching layers, or any combination thereof. For example, withparticular reference to FIG. 10F, a transducer can comprise an imagingelement 1012 having a surface 1028 configured for focusing, defocusingor planar energy distribution, with therapy elements 1014 including astepped-configuration lens configured for focusing, defocusing, orplanar energy distribution.

In accordance with another aspect of the invention, transducer probe 400may be configured to provide one, two or three-dimensional treatmentapplications for focusing acoustic energy to one or more regions ofinterest. For example, as discussed above, transducer probe 400 can besuitably diced to form a one-dimensional array, e.g., a transducercomprising a single array of sub-transduction elements.

In accordance with another exemplary embodiment, transducer probe 400may be suitably diced in two-dimensions to form a two-dimensional array.For example, with reference to FIG. 9, an exemplary two-dimensionalarray 900 can be suitably diced into a plurality of two-dimensionalportions 902. Two-dimensional portions 902 can be suitably configured tofocus on the treatment region at a certain depth, and thus providerespective slices 904 of the treatment region. As a result, thetwo-dimensional array 900 can provide a two-dimensional slicing of theimage place of a treatment region, thus providing two-dimensionaltreatment.

In accordance with another exemplary embodiment, transducer probe 400may be suitably configured to provide three-dimensional treatment. Forexample, to provide three dimensional treatment of a region of interest,with reference again to FIG. 3, a three-dimensional system can comprisetransducer probe 400 configured with an adaptive algorithm, such as, forexample, one utilizing three-dimensional graphic software, contained ina control system, such as control system 300. The adaptive algorithm issuitably configured to receive two-dimensional imaging, temperatureand/or treatment information relating to the region of interest, processthe received information, and then provide correspondingthree-dimensional imaging, temperature and/or treatment information.

In accordance with an exemplary embodiment, with reference again to FIG.9, an exemplary three-dimensional system can comprise a two-dimensionalarray 900 configured with an adaptive algorithm to suitably receiveslices 904, 907 from different image planes of the treatment region,process the received information, and then provide volumetricinformation 906, e.g., three-dimensional imaging, temperature and/ortreatment information. Moreover, after processing the receivedinformation with the adaptive algorithm, the two-dimensional array 900may suitably provide therapeutic heating to the volumetric region 906 asdesired.

Alternatively, rather than utilizing an adaptive algorithm, such asthree-dimensional software, to provide three-dimensional imaging and/ortemperature information, an exemplary three-dimensional system cancomprise a single transducer 404 configured within a probe arrangementto operate from various rotational and/or translational positionsrelative to a target region.

To further illustrate the various structures for transducer 404, withreference to FIG. 7, ultrasound therapy transducer 700 can be configuredfor a single focus, an array of foci, a locus of foci, a line focus,and/or diffraction patterns. Transducer 700 can also comprise singleelements, multiple elements, annular arrays, one-, two-, orthree-dimensional arrays, broadband transducers, and/or combinationsthereof, with or without lenses, acoustic components, and mechanicaland/or electronic focusing. Transducers configured as sphericallyfocused single elements 702, annular arrays 704, annular arrays withdamped regions 706, line focused single elements 708, 1-D linear arrays710, 1-D curvilinear arrays 712 in concave or convex form, with orwithout elevation focusing, 2-D arrays 714, and 3-D spatial arrangementsof transducers may be used to perform therapy and/or imaging andacoustic monitoring functions. For any transducer configuration,focusing and/or defocusing may be in one plane or two planes viamechanical focus 720, convex lens 722, concave lens 724, compound ormultiple lenses 726, planar form 728, or stepped form, such asillustrated in FIG. 10F. Any transducer or combination of transducersmay be utilized for treatment. For example, an annular transducer may beused with an outer portion dedicated to therapy and the inner diskdedicated to broadband imaging wherein such imaging transducer andtherapy transducer have different acoustic lenses and design, such asillustrated in FIG. 10C-10F.

Various shaped treatment lesions can be produced using the variousacoustic lenses and designs in FIGS. 10A-10F. For example, mushroomshaped lesions may be produced from a spherically focused source, and/orplanar lesions from a flat source. That is, as the application ofablative ultrasound energy continues, this causes thermal expansion togenerate a growing lesion. Concave planar sources and arrays can producea “V-shaped” or ellipsoidal lesion. Electronic arrays, such as a lineararray, can produce defocused, planar, or focused acoustic beams that maybe employed to form a wide variety of additional lesion shapes atvarious depths. An array may be employed alone or in conjunction withone or more planar or focused transducers. Such transducers and arraysin combination produce a very wide range of acoustic fields and theirassociated benefits. A fixed focus and/or variable focus lens or lensesmay be used to further increase treatment flexibility. A convex-shapedlens, with acoustic velocity less than that of superficial tissue, maybe utilized, such as a liquid-filled lens, gel-filled or solid gel lens,rubber or composite lens, with adequate power handling capacity; or aconcave-shaped, low profile, lens may be utilized and composed of anymaterial or composite with velocity greater than that of tissue. Whilethe structure of transducer source and configuration can facilitate aparticular shaped lesion as suggested above, such structures are notlimited to those particular shapes as the other spatial parameters, aswell as the temporal parameters, can facilitate additional shapes withinany transducer structure and source.

Through operation of ultrasound system 100, a method for treatment ofcellulite can be realized that can facilitate effective and efficienttherapy without creating chronic injury to human tissue. For example, auser may first select one or more transducer probe configurations fortreating a region of interest. The user may select any probeconfiguration described herein. Because the treatment region ranges fromapproximately 0 mm to 3.5 cm, exemplary transducer probes may include,for example, an annular array, a variable depth transducer, amechanically moveable transducer, a cylindrical-shaped transducer, alinear or flat transducer and the like. As used herein, the term usermay include a person, employee, doctor, nurse, and/or technician,utilizing any hardware and/or software of other control systems.

Once one or more transducers are selected, the user may then image aregion of interest in order to plan a treatment protocol. By imaging aregion of interest, the user may user the same treatment transducerprobe and/or one or more additional transducers to image the region ofinterest at a high resolution. In one embodiment, the transducer may beconfigured to facilitate high speed imaging over a large region ofinterest to enable accurate imaging over a large region of interest. Inanother embodiment, ultrasound imaging may include the use of Dopplerflow monitoring and/or color flow monitoring. In addition other means ofimaging such as photography and other visual optical methods, MRI,X-Ray, PET, infrared or others can be utilized separately or incombination for imaging and feedback of the superficial tissue and thevascular tissue in the region of interest.

In accordance with another exemplary embodiment, with reference to FIG.12, an exemplary treatment system 200 can be configured with and/orcombined with various auxiliary systems to provide additional functions.For example, an exemplary treatment system 1200 for treating a region ofinterest 1206 can comprise a control system 1202, a probe 1204, and adisplay 1208. Treatment system 1200 further comprises an auxiliaryimaging modality 1274 and/or auxiliary monitoring modality 1272 may bebased upon at least one of photography and other visual optical methods,magnetic resonance imaging (MRI), computed tomography (CT), opticalcoherence tomography (OCT), electromagnetic, microwave, or radiofrequency (RF) methods, positron emission tomography (PET), infrared,ultrasound, acoustic, or any other suitable method of visualization,localization, or monitoring of cellulite within region-of-interest 1206,including imaging/monitoring enhancements. Such imaging/monitoringenhancement for ultrasound imaging via probe 1204 and control system1202 could comprise M-mode, persistence, filtering, color, Doppler, andharmonic imaging among others; furthermore an ultrasound treatmentsystem 1270, as a primary source of treatment, may be combined with asecondary source of treatment 1276, including radio frequency (RF),intense pulsed light (IPL), laser, infrared laser, microwave, or anyother suitable energy source.

Because the location and thickness of the fat lobuli varies from onepatient to another (due to genetics, weight, age, etc.), imaging using atransducer can facilitate treatment within a patient, however imaging isnot required to treat cellulite.

By planning a treatment protocol, the user may choose one or morespatial and/or temporal characteristics to provide conformal ultrasoundenergy to a region of interest. For example, the user may select one ormore spatial characteristics to control, including, for example, the useone or more transducers, one or more mechanical and/or electronicfocusing mechanisms, one or more transduction elements, one or moreplacement locations of the transducer relative to the region ofinterest, one or more feedback systems, one or more mechanical arms, oneor more orientations of the transducer, one or more temperatures oftreatment, one or more coupling mechanisms and/or the like.

In addition, the user may choose one or more temporal characteristics tocontrol in order to facilitate treatment of the region of interest. Forexample, the user may select and/or vary the treatment time, frequency,power, energy, amplitude and/or the like in order to facilitate temporalcontrol. For more information on selecting and controlling ultrasoundspatial and temporal characteristics, see U.S. application Ser. No.11/163,148, entitled “Method and System for Controlled Thermal Injury,”filed Oct. 6, 2005 and previously incorporated herein by reference.

After planning of a treatment protocol is complete, the treatmentprotocol can be implemented. That is, a transducer system can be used todeliver ultrasound energy to a treatment region to ablate select tissuein order to facilitate cellulite treatment. By delivering energy, thetransducer may be driven at a select frequency, a phased array may bedriven with certain temporal and/or spatial distributions, a transducermay be configured with one or more transduction elements to providefocused, defocused and/or planar energy, and/or the transducer may beconfigured and/or driven in any other ways hereinafter devised.

In one exemplary embodiment, energy is delivered in relatively smallablative areas in order to minimize and/or prevent scar tissue fromforming. That is, each ablative area of treatment can range fromapproximately 100 microns to 55 mm in diameter. In another exemplaryembodiment, ultrasound energy is used in a “lawnmower” type fashion toevenly ablate a treatment region to provide a substantially planarsurface of lobuli. This “lawnmower”-type ablation in turn, helps toachieve a substantially smooth surface of the epidermis.

In one exemplary embodiment, energy is delivered at a treatment depth ofapproximately 0 mm to 3.5 cm. The energy may range from 750 kHz to about10 MHz, with typical applications ranging from 2 MHz to 10 MHz. In orderto deliver energy in this treatment range, the transducer can be drivenat power levels ranging from 20 W to 200 W. Because treatment time andtreatment power are interrelated, these variables may differ from onepatient to another and/or from one region of interest to another.

Once the treatment protocol has been implemented, the region of tissuemay have one or more reactions to the treatment. For example, in oneembodiment, the tissue responds by enhancement of lymphatic drainage,evacuation of fat decay products, creation of a thermal injury and/orcoagulation of proximal protrusions of fat lobuli.

Upon treatment, the steps outlined above can be repeated one or moreadditional times to provide for optimal treatment results. Differentablation sizes and shapes may affect the recovery time and time betweentreatments. For example, in general, the larger the surface area of thetreatment lesion, the faster the recovery. The series of treatments canalso enable the user to tailor additional treatments in response to apatient's responses to the ultrasound treatment.

The present invention has been described above with reference to variousexemplary embodiments. However, those skilled in the art will recognizethat changes and modifications may be made to the exemplary embodimentswithout departing from the scope of the present invention. For example,the various operational steps, as well as the components for carryingout the operational steps, may be implemented in alternate waysdepending upon the particular application or in consideration of anynumber of cost functions associated with the operation of the system,e.g., various steps may be deleted, modified, or combined with othersteps. These and other changes or modifications are intended to beincluded within the scope of the present invention, as set forth in thefollowing claims.

What is claimed is:
 1. An ultrasound probe, comprising: a piezoelectricultrasound therapy element connected to a motion mechanism, wherein thepiezoelectric ultrasound therapy element is configured for acousticcoupling through the probe to a skin surface, wherein the piezoelectricultrasound therapy element is configured for focusing ultrasound energywith a frequency to produce a temperature at a depth under the skinsurface to coagulate fat cells in fat lobuli that protrude into a dermistissue that creates an appearance of dimpling of the skin surfaceassociated with cellulite, wherein the motion mechanism is configured tooperate with an encoder configured to determine movement of thepiezoelectric ultrasound therapy element within the probe, wherein themotion mechanism moves the piezoelectric ultrasound therapy element toform one or more thermal foci at the depth for coagulating fat therebyreducing the appearance of dimpling of the skin associated withcellulite.
 2. The probe of claim 1, wherein the encoder is configuredfor monitoring a position of the piezoelectric ultrasound therapyelement on the motion mechanism in a housing of the ultrasound probe,wherein the piezoelectric ultrasound therapy element is a single elementthat focuses the ultrasound energy operating at the frequency rangingfrom 2 MHz to 10 MHz, wherein the ultrasound energy is delivered with atreatment power ranging from 20 W to 200 W, wherein the piezoelectricultrasound therapy element is configured to deliver the ultrasoundenergy at the depth below the skin surface, wherein the ultrasoundenergy generates a thermal lesion with a dimension of between 100microns to 55 mm in a region of interest.
 3. The probe of claim 1,wherein the piezoelectric ultrasound therapy element is at least one ofthe group consisting of spherically focused and cylindrically focused.4. The probe of claim 1, wherein the ultrasound energy increases a speedat which fat metabolizes according to Arrhenius Law: Y=A·e^(−B/T), whereY is a yield of metabolic reaction, A and B are constants, and T is atemperature in degrees Kelvin.
 5. The probe of claim 1, wherein thepiezoelectric ultrasound therapy element is configured to operate with acontrol system comprising a processor, wherein the piezoelectricultrasound therapy element is configured for communication with thecontrol system, wherein the probe is disposable.
 6. The probe of claim1, wherein the motion mechanism is a linear motion mechanism for linearmovement of the piezoelectric ultrasound therapy element to form aplurality of thermal lesions along a line at the depth in a region ofinterest.
 7. The probe of claim 1, further comprising a imaging deviceselected from the group consisting of: ultrasound, MRI, X-ray, PET, andinfrared.
 8. The probe of claim 1, further comprising an imaging deviceco-housed with the piezoelectric ultrasound therapy element.
 9. Theprobe of claim 1, wherein the motion mechanism is configured for atleast one of the group consisting of linear and rotational movement ofthe piezoelectric ultrasound therapy element.
 10. An ultrasound probe,comprising: a piezoelectric ultrasound therapy element configured foracoustic coupling through the ultrasound probe to a skin surface,wherein a fat chamber containing a plurality of fat cells protrudes intoa dermis under the skin surface, wherein the piezoelectric ultrasoundtherapy element is configured to focus energy with a frequency toproduce a temperature sufficient to coagulate the plurality of fat cellsin the fat chamber at a depth under the skin surface, thereby reducingan appearance of dimpling on the skin surface.
 11. The probe of claim10, wherein the piezoelectric ultrasound therapy element is a singleelement that focuses ultrasound energy with the frequency ranging from 2MHz to 10 MHz, wherein the ultrasound energy is delivered with atreatment power ranging from 20 W to 200 W, wherein the piezoelectricultrasound therapy element is configured to focus the ultrasound energyup to 3.5 cm below the skin surface, wherein the ultrasound energygenerates a thermal lesion with a dimension of between 100 microns to 55mm in a region of interest.
 12. The probe of claim 10, wherein theultrasound probe comprises a housing containing an imaging device,wherein the imaging device is configured for imaging a region ofinterest under the skin surface, wherein the region of interestcomprises a tissue, wherein the tissue comprises the fat chamber,wherein the probe is disposable.
 13. The probe of claim 10, wherein thepiezoelectric ultrasound therapy element is a single element thatdelivers ultrasound energy, wherein the frequency ranges from 750 kHz to10 MHz, and wherein the ultrasound energy increases a speed at which fatmetabolizes according to Arrhenius Law: Y=A·e^(−B/T), where Y is a yieldof metabolic reaction, A and B are constants, and T is a temperature indegrees Kelvin.
 14. The probe of claim 10, further comprising a storagesystem configured to contain at least one of the group consisting of:probe identification and probe usage history, wherein the piezoelectricultrasound therapy element is configured for connection to a controlsystem, wherein the control system comprises: a processor, software, apower supply, and a communication device.
 15. An ultrasound probe,comprising: a housing, a piezoelectric ultrasound therapy element, and amotion mechanism, wherein the piezoelectric ultrasound therapy elementfocuses ultrasound energy to a tissue below a skin surface at afrequency ranging from 2 MHz to 10 MHz, wherein the tissue comprises aplurality of fat chambers that protrude into a dermis to create anappearance of dimpled skin, wherein the piezoelectric ultrasound therapyelement is configured for delivery of the ultrasound energy at atemperature sufficient to coagulate at least a portion of a plurality offat chambers at a depth under the skin surface, wherein thepiezoelectric ultrasound therapy element is connected to the motionmechanism inside the housing, wherein the motion mechanism is configuredto operate with an encoder, wherein the motion mechanism moves thepiezoelectric ultrasound therapy element to form a plurality of thermallesions at the depth for reducing an appearance of dimpled skin.
 16. Theprobe of claim 15, wherein the piezoelectric ultrasound therapy elementis a single element, wherein the piezoelectric ultrasound therapyelement is configured to deliver the ultrasound energy at the depthbelow the skin surface, wherein the depth is a single, fixed depth,wherein the ultrasound energy generates a thermal lesion with adimension of between 100 microns to 55 mm in a region of interest. 17.The probe of claim 15, wherein the piezoelectric ultrasound therapyelement is configured to operate with a control system that comprises aspatial control and a temporal control, the spatial control and thetemporal control controlling the delivery of the ultrasound energy at atemperature sufficient to cause coagulation of at least the portion ofthe plurality of fat chambers at the depth under the skin surface,wherein the ultrasound energy is delivered with a treatment powerranging from 20 W to 200 W.
 18. The probe of claim 17, furthercomprising a storage system comprising probe identification and probeusage history, wherein the probe is disposable.
 19. The probe of claim15, wherein the ultrasound energy increases a speed at which fatmetabolizes according to Arrhenius Law: Y=A·e^(−B/T), where Y is a yieldof metabolic reaction, A and B are constants, and T is a temperature indegrees Kelvin.
 20. The probe of claim 15, wherein the piezoelectricultrasound therapy element is configured to deliver the ultrasoundenergy at an energy level for causing at least one of ablating tissue,stretching fibrous bonds, or stimulating evacuation of fat decayproducts in a region of interest.